Hirata Kazuné, Shiga Sakiko
Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka 560-0043, Osaka, Japan.
Center for Ecological Research, Kyoto University, Otsu 520-2133, Shiga, Japan.
Insects. 2023 Jan 23;14(2):115. doi: 10.3390/insects14020115.
Flesh-fly larvae exhibit a photoperiodic response, in which short days induce pupal diapause for seasonal adaptation. Although the spectral sensitivity of photoperiodic photoreception is known, the photoreceptor organ remains unclear. We morphologically identified the Bolwig organ, a larval-photoreceptor identified in several other fly species, and examined the effects of its removal on the photoperiodic response in . Backfill-staining and embryonic-lethal-abnormal-vision (ELAV) immunohistochemical-staining identified ~34 and 38 cells, respectively, in a spherical body at the ocular depression of the cephalopharyngeal skeleton, suggesting that the spherical body is the Bolwig organ in . Forward-fill and immunohistochemistry revealed that Bolwig-organ neurons terminate in the vicinity of the dendritic fibres of pigment-dispersing factor-immunoreactive and potential circadian-clock neurons in the brain. After surgical removal of the Bolwig-organ regions, diapause incidence was not significantly different between short and long days, and was similar to that in the insects with an intact organ, under constant darkness. However, diapause incidence was not significantly different between the control and Bolwig-organ-removed insects for each photoperiod. These results suggest that the Bolwig organ contributes partially to photoperiodic photoreception, and that other photoreceptors may also be involved.
麻蝇幼虫表现出光周期反应，其中短日照会诱导蛹滞育以进行季节性适应。尽管光周期光感受的光谱敏感性是已知的，但光感受器器官仍不清楚。我们从形态学上鉴定了博尔维格氏器官，这是在其他几种蝇类中鉴定出的幼虫光感受器，并研究了切除它对[具体昆虫名称未给出]光周期反应的影响。回填染色和胚胎致死异常视觉（ELAV）免疫组织化学染色分别在头咽骨骼眼窝处的一个球形体中鉴定出约34个和38个细胞，这表明该球形体是[具体昆虫名称未给出]的博尔维格氏器官。正向填充和免疫组织化学显示，博尔维格氏器官神经元在大脑中色素分散因子免疫反应性和潜在生物钟神经元的树突纤维附近终止。在手术切除博尔维格氏器官区域后，短日照和长日照条件下的滞育发生率没有显著差异，并且在持续黑暗条件下与器官完整的昆虫相似。然而，对于每个光周期，对照昆虫和切除博尔维格氏器官的昆虫之间的滞育发生率没有显著差异。这些结果表明，博尔维格氏器官部分参与光周期光感受，并且可能还涉及其他光感受器。
